After spending more than six months out of the sport with a knee injury at the end of last year, there had been doubts over whether Nadal could return to the top, especially on hard courts.

But the 27-year-old Spaniard showed why he now has 13 grand slam titles to his name with a typically physical and powerful four-set victory.

"For a few things, this season is probably the most emotional one in my career. I felt that I did everything right to have my chance here," Nadal said after Monday's final.

"So to play one match against one of the best players of the history like this, Novak, number one in the world, probably on probably his favorite surface, I have to be almost perfect to win.

"It means a lot for me have this trophy with me today. It's just amazing.

"I'm very, very happy, and just thank you very much everybody who helped me to make that possible. It's a really special moment for me."

After missing the opening major of the year in Australia through his injury, Nadal has battled back to finish the year with two grand slams after his win in Paris in June.

Asked if he believed he could achieve what he has in those tough months out injured, Nadal said: "I never thought something like this could happen. . . . I'm so excited to be back on tour trying to be competitive."

"But I never thought about competing for all what I competed this year, no? All the Masters 1000s, two grand slams, or three.

"So (this) is just more than a dream for me, and I'm very happy for everything. I feel very lucky about what happened since I came.

"It's true that I worked, but even like this you need luck to be where I am today."

The decisive moment of the match came with the pair locked at a set apiece and 4-4, with Nadal staring down three break points.

The Spaniard produced some of his best tennis to save all three, including his first ace of the match, to survive the scare before breaking Djokovic in the next game to win the set.

Nadal burst out in an intense celebration after going up two sets to one.

"I really don't know what's going on in that moment . . . it was just was a celebration," Nadal said of his reaction to somehow winning the third set.

"It was a very important point (to) win the third set. After all what happened in that set, it was an amazing victory of that set.

"I make the celebration but I really don't have emotions in that moment. Then you finish the celebration.

"You are walking to the chair and say, 'OK, I won the third. I need to be focused for the beginning of the fourth, because I am serving against the wind and the break is possible for him. I need to save that game.'"

Nadal's 13 grand slams move him into third place overall in men's tennis, four behind Roger Federer and just one behind retired American great Pete Sampras.

Asked if he believed he could surpass those two targets, Nadal smiled: "Let me enjoy today first."

"For me, is much more than what I ever thought, what I ever dreamed. I said that few slams, when I had few slams less, but is true.

"It means a lot, this one, for me. Only thing I can say is the same like I do every time. I'm going to keep working hard.

"I'm going keep doing my things to have more chances in the future to be competitive and to give me produce more chances to win the tournaments like this one.

"So that's what I gonna try. Then you never know when that start, when that finish, but 13 is an amazing number."